Electric-current-controlling device



H. P. DONLE.

ELECTRIC CURRENT CONTROLLING DEVICE. E

APPLICATION FILED FEB.2.1920.

L, Patented Nov. M9 E922..

Patented Nov. 14, 1922.

UNITED STATES PATENT OFFICE.l

HAROLD POTTER DONLE, 0F MERIDEN, CONNECTICUT, ASSIGNOR T0 TH CONNECTICUT TELEPHONE & ELECTRIC'CO. INC., 0F MERIDEN. CONNECTICUT, A CORPORATION 0F CONNECTICUT.

ELECTBIC-CURRENT-CONTROLLING DEVICE.

Application med February 2, 1920. Serial No. 355,620.

To all whom t may concern:

Be it known that I, HAROLD Poi'rmi DoNLn, a citizen of the United States of America, residing at Meriden, Connecticut, have invented a new and useful Electric- Current-Controlling Device, of which the following is a specification.

My invention relates particularly to what is commonly termed a vacuum tube type of device;

The main object is to provide a simple and compact construction which can be economically and readily manufactured, which will produce a maximum effect with a minimum power and be durable under normal conditions of use. n

Another object is to construct a device which with a small power input will produce relatively great variations of output current. l

In its preferred form the tube is of glass and contains a filament having two active portions in series and disposed longitudinally of the tube. This filament constitutes the cathode or emissive element. The anode embraces the tube outside of one portion of the filament and a control electrode or plate embraces the tube adjacent the other portion of the filament. Inside of the tube is an element which may be termed an equalizer, consisting of an annular or cylindrical portion surrounding or partially surrounding one portion of the filament within the infiuence of the control and cathode, and a connected plexus or network interposed between the other portion of the filament and the anode. The annulus and plexus are electrically connected to each other but not metallically connected to anything else.

The tube when in use is preferably surrounded by a ventilated shield through which the condition of the tube may be observed.

Fig. 1 is a side view of a tube construction embodying my invention with the ventilated shield shown in section.

Fig. 2 is a longitudinal sectional view of the tube itself without the ventilated shield.

Fig. 3 is a transverse sectional view on the plane of the line 3-3 of Fig. 2.

Fig. 4 is a transverse sectional View on the plane of the line 4-4 of Fig. 2. Fig. 1s a perspective view of the tube itself with its external electrodes. Fig. 6 1s a detail View of the filament and its supports.

Fig. 7 is a detail perspective view of the equalizer.

The tube 10 is preferably of 'transparent glass such as is ordinarily used in the construction of tubes of this general character. It is preferably cylindrical in form and of relatively small diameter and may be provided with an enlarged base 11 with a stem 12. I consider that the broad term tube, for the purpose of the claims, covers any shape of bulb or globe.

The internal conductor or cathode has a filament which is preferably composedof two parts 13 and 14 suitably constructed to produce a lmaximum emission. These two parts may be connected by a conductor 15 of less resistance so that the heating effect will be confined to portions 13 and 14. This cathode may be Supported b wires 16 and 17 embedded in the stem. lreferably, the outer end of the conductor is positive and the inner end negative. The cathode and its supports may be made of molybdenum, tungsten or other suitable metal. The central part of the conductor may be tied to the support '16 by a non-conducting element 18 so as to reinforce the filament..

The anode or plate 19 is preferably in the form of a metallic deposit on the outside of the tube surrounding the part 14 of the cathode, near the negative end. I have found silver to be particularly useful for this purpose.

The control electrode 20 isalso preferably in the form of a similar deposit on the out.- side of the tube adjacent the filament portion 13 near the positive end. This is shown as a cylinder but it need not be continuous and mayhave a small area but should closely adhere to the glass.

The equalizer may be made of molybdenum or tungsten or other suitable metal. The annulus or c linder 21 preferably fits snugly inside of t e tube and surrounds the unit for inserting it in the tube and when inserted, it is Vsupported at Vits outer end fby the contact of the cylinder 21 inside the tube and at its loivcr end by the tip l2.

Therelcctric connectlons to the tube are effected through the conductors 24, 25, 26

. and 27, which may have terminal contacts on the lower end of the tube such as at 28.

The tubeY mayA be treated as Set forth in in v application #295,897, filed May 9th, 1919, for increasing the electronic emission.

The operation of the equalizer can be described `as charging up to negative potential by the accumulation of electrons at the plexus end thereby reducing the emission from the filamentjat the plexus by repulsion between electrons, and thereafter the modulated dissipation of thisnegative charge at the other end by the action of varying elec-- trical potentials applied to the control electrode 20. The operation-of this tube with the external anode and control, and the internal equalizer is' radically different from that of any vacuum tubes heretofore on the market such as the so-called valves and audions.

The tube may be used either as a. detector, as an amplifier or as an oscillator. lt will be found that only a very small power input is required to get definite variations of anode or output current.' The construction is such that the device may be of a very small size for a given power or conversely a substantially increased power is provided for a given size of tube.- 0n account of the small size the construction is cheap and very easy to free from deleterious gas. As the volume of metal employed is very small, the tube is unusually stable since there is less possibility of harmful gas being given ofi'. So far as l can ascertain, the device is much more sensitive than any other vacuum tube device corresponding in size or cost.

While the tube as thus far described is operative, l find that the operation is much more uniform and stable when a ventilated shield suchv as 30 is employed. This shield is preferably of glass which is transparent so that the degree of incandescence of the filament and the condition of the tube may be readily observed. One or more holes or perforations such as 31 shouldbe provided so as to ventilate the shield. The shield serves to maintain all parts of the tube at substantially the same temperature and thus prevent variationsintthe operation which might occur if drafts were allowed to blow upon the tube and alter the temperature of one part or another relative to the other parts.

By the use of the external anode and con-` trol electrodes in combination with the internal equalizer', l am able to utilize the heated filament for the production of novel effects Aof' current transfer and control which are radically different from those obtained by the use of internal anode or control electrodes.

l claim: e Y

1. ln a construction of the character described, a tube, au internal cathode, an external anode surrounding one part of the cathode, an external control adjacent another part of the cathode and spaced apart from the anode and an equalizer inside of the tube having a portion interposed between the control and the cathode and another portion connected with the first portion and inter-- posed between thecathode and the anode.

2. In a construction of the character described, a tube, an internal electrode having two portions in series disposed longitudinally of the tube, an anode on the outside of the tube adjacent one portion of the inner electrode, a control on the outside of the tube adjacent the other portion of the inner electrode, and an equalizer on the inside of the tube having portions interposed between the inner electrode and the anode and control respectively.

3. lin a construction of the character described, a tube, an inner electrode, two outer electrodes on the tube spaced apart from each other, and an equalizer supported inside of the tube between the inner and outer electrodes and separated from the inner and outer electrodes.

4. in a construction of the character described, a tube, a filament inside said tube. a plexus surrounding one portion of said filament inside the tube, an annulus surrounding another portion of the filament inside the tube and connected to said plexus, an anode, and a control element outside the tube.

5. ln a construction of the character described, a tube, a filament inside said tube, a plexus surrounding one portion of said fila-ment inside the tube, an annulus surrounding another portion of the filament inside the tube in contact with the inner wall of the tube and connected to said plexus, an anode in contact with the tube, and a control element outside of the tube.

6. ln a construction of the character described, a tube, an internal filament cathode, an external cylindrical anode surrounding one part of the cathode, an external annular control surrounding another part of the cathode and spaced apart from the anode and an equalizer inside of the tube having an annulus interposedbetween the control and the cathode and a plexus electrically i connected with the annulus and interposed between the cathode and the anode.

7. In a construction of the character described, a tube, an internal electrode having two portions in series disposed longitudinally of the tube, an anode embracing the outside of the tube adjacent one portion of the inner electrode, a control embracing the outside of the tube adjacent the other portion of the inner electrode, and an equalizer on the inside of the tube having a portion in contact with the tube between the inner electrode and the anode and another portion between the inner electrode and the control.

8. In a construction of the character described, a relatively long tubeof small diameter, anv inner electrode, two outer electrodes on the -tube spaced apart from each other,

and an equalizer supported inside of the tube between the inner and outer electrodes, and having a non-perforated portion and a plexus respectively co-acting with the two outer, electrodes.

9. In a construction ofthe character described, the combination of a tube, an 'inter` nal electrode, two electrodes spaced apart from each other on the outside of said tube and a ventilated transparent shield sur-V rounding said tube and said external electrodes for maintaining uniformity of conditions but to permit observation of the tube.

10. In a construction of the character described, the combination of a tube, an internal electrode, two electrodes spaced apart from each other on the outside of said tube and a ventilated transparent shield surrounding said tube and said external electrodes for maintaining uniformity of conditions but to permit observation of the tube, an equalizer surrounding said electrode inside the tube.

11. In a construction of the character described, the combination of a tube, an internal filament, two electrodes spaced apart from each other and surrounding the outside of said tube and a ventilated shield surrounding said tube and said external electrodes but spaced apart therefrom for maintaining uniformity of conditions but permitting observation of the tube.

12. In a construction of the character described, a tube, a divided filament inside said tube, a plexus adjacent and co-operating with one portion of said filament within said tube, a conducting member adjacent and co-operating with another portion of the filament inside said tube and connected to said plexus, an anode adjacent said plexus and a control element adjacent said conduting member but on the outside of said tu e.

13. In a construction of the character described, two filamentary members connected together in series, a plexus adjacent and cooperating with one of said members, an imperforate element adjacent and co-operating with the other member and connected to said plexus, an anode adjacent said plexus and a control element adjacent said imperforate member.

14. Ina construction of the character described, a filament, a plexus surrounding and co-operating with one portion of said filament, an annulus surrounding and cooperatin with another portion of said filament an connected to said plexus, an anode adjacent said plexus and a control element adjacent said annulus.

15. In a construction of the character described, a tube, a filament extending longitudinally of thetube and supported at one end of the tube, a conductor supported at the same end of the, tube, a plexus carried by said conductor surrounding one portion of said filament, and an annulus supported at the other end of .said conductor and surrounding another portion of said filament.

16. In a construction of the character described, a tube, a filament extending'longia vacuum tube, an internal filament, an l electrode on the outer surface of the tube, and a ventilated shield surrounding the tube and the outer electrode but spaced apart therefromfor maintaining substantial uniformity-.of conditions during operation of th?) device but permitting observation of the tu e. '4

18. In a device of the character described, a vacuum tube, an internal cathode, an anode on the outer surface ofthe tube adjacent the cathode, and a ventilated shield surrounding said tube and its anode to prevent fiuctuation of temperature and to permit observation of the condition of the tube.

HAROLD POTTER DONLE. 

